SERVICE MANUAL

5PG-28197-10

LIT-11616-20-15

PW50W

PW50W

SERVICE MANUAL

©2006 by Yamaha Motor Corporation,

U.S.A.

First edition, May 2006

All rights reserved.

Any reproduction or unauthorized use

without the written permission of

Yamaha Motor Corporation, U.S.A.

is expressly prohibited.

Printed in U.S.A.

P/N LIT-11616-20-15

EAS00000

NOTICE

This manual was produced by the Yamaha Motor Company, Ltd. primarily for use by Yamaha dealers

and their qualified mechanics. It is not possible to include all the knowledge of a mechanic in one

manual. Therefore, anyone who uses this book to perform maintenance and repairs on Yamaha vehi-

cles should have a basic understanding of mechanics and the techniques to repair these types of

vehicles. Repair and maintenance work attempted by anyone without this knowledge is likely to ren-

der the vehicle unsafe and unfit for use.

This model has been designed and manufactured to perform within certain specifications in regard

to performance and emissions. Proper service with the correct tools is necessary to ensure that the

vehicle will operate as designed. If there is any question about a service procedure, it is imperative

that you contact a Yamaha dealer for any service information changes that apply to this model. This

policy is intended to provide the customer with the most satisfaction from his vehicle and to conform

to federal environmental quality objectives.

Yamaha Motor Company, Ltd. is continually striving to improve all of its models. Modifications and

significant changes in specifications or procedures will be forwarded to all authorized Yamaha dealers

and will appear in future editions of this manual where applicable.

NOTE:

8This Service Manual contains information regarding periodic maintenance to the emission control

system. Please read this material carefully.

8Designs and specifications are subject to change without notice.

IMPORTANT MANUAL INFORMATION

Particularly important information is distinguished in this manual by the following.

Q

The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR SAFETY

IS INVOLVED!

w

Failure to follow WARNING instructions could result in severe injury or death to the

vehicle operator, a bystander or a person checking or repairing the vehicle.

cC

A CAUTION indicates special precautions that must be taken to avoid damage to

the vehicle.

NOTE:

A NOTE provides key information to make procedures easier or clearer.

HOW TO USE THIS MANUAL

This manual is intended as a handy, easy-to-read reference book for the mechanic.

Comprehensive explanations of all installation, removal, disassembly, assembly, repair and check

procedures are laid out with the individual steps in sequential order.

1 The manual is divided into chapters. An abbreviation and symbol in the upper right corner of

each page indicate the current chapter.

Refer to "SYMBOLS".

2 Each chapter is divided into sections. The current section title is shown at the top of each page,

except in Chapter 3 ("PERIODIC CHECKS AND ADJUSTMENTS"), where the sub-section title(s)

appears.

3 Sub-section titles appear in smaller print than the section title.

4 To help identify parts and clarify procedure steps, there are exploded diagrams at the start of

each removal and disassembly section.

5 Numbers are given in the order of the jobs in the exploded diagram. A circled number indicates

a disassembly step.

6 Symbols indicate parts to be lubricated or replaced.

Refer to "SYMBOLS".

7 A job instruction chart accompanies the exploded diagram, providing the order of jobs, names

of parts, notes in jobs, etc.

8 Jobs requiring more information (such as special tools and technical data) are described

sequentially.

1

2

6

3

5

4

7

8

SYMBOLS

The following symbols are not relevant to

every vehicle.

Symbols 1 to 8 indicate the subject of each

chapter.

1 General information

2 Specifications

3 Periodic checks and adjustments

4 Chassis

5 Engine

6 Carburetor

7 Electrical system

8 Troubleshooting

Symbols 9 to y indicate the following.

9 Serviceable with engine mounted

0 Filling fluid

q Lubricant

w Special tool

e Tightening torque

r Wear limit, clearance

t Engine speed

y Electrical data

Symbols u to s in the exploded diagrams

indicate the types of lubricants and lubrication

points.

u Engine oil

i Gear oil

o Molybdenum-disulfide oil

p Wheel-bearing grease

a Lithium-soap-based grease

s Molybdenum-disulfide grease

Symbols d to f in the exploded diagrams

indicate the following.

d Apply locking agent (LOCTITE^®)

f Replace the part

1

2

3

4

5

6

7

8

9

0

q

w

e

r

t

y

u

i

o

p

a

s

d

f

GEN

INFO

SPEC

CHK

ADJ

ENG

CARB

CHAS

ELEC

TRBL

SHTG

LT

New

SPECIFICATIONS

TROUBLESHOOTING

ELECTRICALSYSTEM

CARBURETOR

CHASSIS

PERIODIC CHECKS AND

ADJUSTMENTS

GENERALINFORMATION

GEN

INFO

TRBL

SHTG

ELEC

CARB

CHAS

CHK

ADJ

SPEC

TABLE OF CONTENTS

4

6

7

8

3

2

1

ENGINE

ENG 5

GEN

INFO

CHAPTER 1

GENERAL INFORMATION

VEHICLE IDENTIFICATION .............................................................................1-1

VEHICLE IDENTIFICATION NUMBER .......................................................1-1

ENGINE SERIAL NUMBER .........................................................................1-1

IMPORTANT INFORMATION............................................................................1-2

PREPARATION FOR REMOVAL AND DISASSEMBLY ..............................1-2

REPLACEMENT PARTS .............................................................................1-2

GASKETS, OIL SEALS AND O-RINGS ......................................................1-2

LOCK WASHERS/PLATES AND COTTER PINS .......................................1-3

BEARINGS AND OIL SEALS ......................................................................1-3

CIRCLIPS ....................................................................................................1-3

CHECKING THE CONNECTIONS ...................................................................1-4

SPECIAL TOOLS .............................................................................................1-5

1-1

GEN

INFO

VEHICLE IDENTIFICATION

GENERAL INFORMATION

VEHICLE IDENTIFICATION

VEHICLE IDENTIFICATION NUMBER

The number 1 is stamped into the frame

head pipe.

ENGINE SERIAL NUMBER

The engine serial number 1 is stamped into

the crankcase.

NOTE:

Designs and specifications are subject to

change without notice.

1

1

GEN

INFO

IMPORTANT INFORMATION

IMPORTANT INFORMATION

PREPARATION FOR REMOVAL AND DIS-

ASSEMBLY

1. Before removal and disassembly, remove

all dirt, mud, dust and foreign material.

2. Use only the proper tools and cleaning

equipment.

Refer to the “SPECIAL TOOLS”.

3. When disassembling, always keep mated

parts together. This includes gears, cylin-

ders, pistons and other parts that have

been “mated” through normal wear.

Mated parts must always be reused or

replaced as an assembly.

4. During disassembly, clean all of the parts

and place them in trays in the order of

disassembly. This will speed up assembly

and allow for the correct installation of all

parts.

5. Keep all parts away from any source of

fire.

1-2

EAS00021

REPLACEMENT PARTS

Use only genuine Yamaha parts for all

replacements. Use oil and grease recom-

mended by Yamaha for all lubrication jobs.

Other brands may be similar in function and

appearance, but inferior in quality.

EAS00022

GASKETS, OIL SEALS AND O-RINGS

1. When overhauling the engine, replace all

gaskets, seals and O-rings. All gasket

surfaces, oil seal lips and O-rings must be

cleaned.

2. During reassembly, properly oil all mating

parts and bearings and lubricate the oil

seal lips with grease.

BEARINGS AND OIL SEALS

Install bearings and oil seals so that the man-

ufacturer’s marks or numbers are visible.

When installing oil seals, lubricate the oil seal

lips with a light coat of lithium-soap-based

grease. Oil bearings liberally when installing,

if appropriate.

1 Oil seal

cC

Do not spin the bearing with compressed

air because this will damage the bearing

surfaces.

1 Bearing

CIRCLIPS

Before reassembly, check all circlips carefully

and replace damaged or distorted circlips.

Always replace piston pin clips after one use.

When installing a circlip 1, make sure the

sharp-edged corner 2 is positioned opposite

the thrust 3 that the circlip receives.

4 Shaft

GEN

INFO

IMPORTANT INFORMATION

1

300-000

300-003

1

300-002

1

300-001

3

4

1

2

LOCK WASHERS/PLATES AND COTTER

PINS

After removal, replace all lock washers/plates

1 and cotter pins. After the bolt or nut has

been tightened to specification, bend the lock

tabs along a flat of the bolt or nut.

1-3

GEN

INFO

CHECKING THE CONNECTIONS

1

CHECKING THE CONNECTIONS

Check the leads, couplers, and connecters for

stains, rust, moisture, etc.

1. Disconnect:

9 lead

9 coupler

9 connector

2. Check:

9 lead

9 coupler

9 connector

Moisture →Dry with compressed air.

Rust/stains →Connect and disconnect

several times.

3. Check:

9 all connections

Loose connection →Connect properly.

NOTE:

If the pin 1 on the terminal is flattened, bend

it up.

4. Connect:

9 lead

9 coupler

9 connector

NOTE:

Make sure all connections are tight.

5. Check:

9 continuity

(with the pocket tester)

NOTE:

8If there is no continuity, clean the terminals.

8When checking the wire harness, perform

steps (1) to (3).

8As a quick remedy, use a contact revitalizer

available at most part stores.

1-4

Pocket tester

90890-03112, YM-03112

GEN

INFO

SPECIAL TOOLS

1-5

SPECIAL TOOLS

The following special tools are necessary for complete and accurate tune-up and assembly. Use

only the appropriate special tools as this will help prevent damage caused by the use of inappro-

priate tools or improvised techniques. Special tools, part numbers or both may differ depending on

the country.

When placing an order, refer to the list provided below to avoid any mistakes.

90890-01235

YU-01235

Rotor holding tool

This tool is necessary for removing and

installing the rotor.

90890-01252

Dial gauge and stand set

These tools are for measuring the

crankshaft runout.

Crankshaft instoller pot

This tool is necessary for installing the

crankshaft.

90890-01274

YU-90058

Tool No.

Tool name/Usage

Illustration

90890-01275

YU-90060

Crankshaft installer bolt

This tool is necessary for installing the

crankshaft.

90890-01278

YU-90063

Adapter (M12)

This tool is necessary for installing the

crankshaft.

90890-01189

YM-01189

Flywheel puller

This tool is used for removing the rotor.

90890-01306

YM-01306

Hex. wrench (25 mm)

This tool is needed for removing the mid-

dle gear screw.

GEN

INFO

SPECIAL TOOLS

1-6

90890-03112

YU-03112-U

Pocket tester

This instrument is necessary for

checking the electrical system.

Tool No.

Tool name/Usage

Illustration

Flywheel puller

This tool is used for separating the

crankcase.

90890-01362

YU-33270

90890-06754

YM-34487

Ignition checker

This instrument is necessary for check-

ing the ignition system components.

90890-01307

YM-01307

Hex. wrench (22 mm)

This tool is needed for removing the

shaft drive screw.

90890-06760

YU-06760

Digital tachometer

This tool is needed for observing engine

r/min.

90890-85505

Yamaha bond No.1215

(Three bond No.1215^)

This bond is used on crankcase

mating surfaces,etc.